Sodium Iodide → 2-Ethyl-3-iodopyrazolo[1,5-a]pyridine

Participants

Reaction Steps

N-Chlorosuccinimide (411 g, 3.08 mol) was gradually added to a mixture of 2-ethylpyrazolo[1,5-a]pyridine (360 g, 2.46 mol), ethyl acetate (3600 mL), water (1800 mL) and sodium iodide (480 g, 3.20 mol, 1.3 equivalents) over a period of 30 minutes while cooling with ice, and then the reaction mixture was stirred for 2 hours and 20 minutes at room temperature. After the reaction, water and ethyl acetate were added to the reaction mixture and extraction was performed with ethyl acetate. The organic extract was washed twice with 10% aqueous sodium thiosulfate, and then concentrated. Hexane was added to the residue, the mixture was heated to dissolution and the resulting solution was filtered to remove insoluble residue. After then washing the hexane solution with water, the hexane layer was concentrated, the residue was dissolved in ethyl acetate and the solvent was evaporated to afford 663 g of the title compound (98.9% yield).

Provenance & Evidence